Radical Substitutions of Azo Compounds

Treatment of γ-(p-nitrophenylazo)-γ-valerolactone with benzoyl peroxide in benzene at 85°, yields p-nitroazobenzene and p-nitrobiphenyl. Similarly, α-methyl-α-phenylazotetrahydrofuran yields azo-benzene. Radical substitution at azo nitrogen and at N-bearing benzenoid carbon are the suggested mechanisms. Such reactions of aryl azo compounds have not been reported previously.